Refrigerating apparatus



Oct. 6, 1931. H. B. HULL ET AL 1,825,664

REFRIGERATING APPARATUS Filed Feb. 29, 1928 s Sheets-Sheet 1 M (a M @071 INVENTORS BY M W 7AQATTokNEYs.

Oct. 6, 1931. H. B. HULL ET AL 1,825,664

REFRIGERATING APPARATUS Filed Feb. 29, 1928 3 Sheets-Sheet 2 a2 17 15 aaI 0 U Z2 INVETORS I BY v1 8, I 2 F 7 ATTORNEYS.

Oct. 6, 1931. v H. B. HULL ET AL 1,825,664

REFRIGERATING APPARATUS Filed Feb. 29. 1928 3 Sheets-Sheet 3 PatentedOct. 6, 1931 UNITED STATES" PATENT OFFICE HARRY B. HULL AND GEORGE E.HOFFERBEBTH, OF DAYTON, OHIO, ASSIGNORS TO FRIGIDAIRE CORPORATION, OFDAYTON, OHIO, A CORPORATION OF DELAWARE anrnream'rme ArranuusApplication. filed February 29, 1928. Serial 170. 257,990.

This invention relates to refrigerating apparatus particularly tocabinets for storing small frozen confections such as those known aseskimo pies.

. One of the objects of the invention is to provide a compact andconvenient self-con- I tained refrigerating cabinet which can beconveniently placed in stores and other places having a limited amountof space.

Another object of the invention is to provide an improved and simplifiedform of refrigerating apparatus for maintaining very low temperatures.

Another object of the invention is to provide an improved and simplifiedform of cabinet construction.

Still another object of the invention is to provide an improvedevaporator which prevents flooding of the refrigerating machine.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had tothe accompanyingdrawings. wherein a preferred form of the present invention is 8 clearlyshown. 1

Inthe drawings: 1 Fig. 1 is a perspective view partly broke away of arefrigerating apparatus constructed in accordance with the present in-80 vention:

Fig. 2 is a vertical elevation partly in section through therefrigerating apparatus. the refrigerating machine being shown inelevation; and

Fig. 3 is a corresponding section taken at right angles to Fig. 2.

Referring to Fig. 1. 1O designates a cabinet having a refrigeratingcompartment 11, cooled by an evaporator 12; and a machine compartment 13containing a condensing element generally denoted by 16 for circulatingrefrigerant through the evaporator. The refrigerating compartment isdisposed above the machine compartment in order to reduce te floor spaceoccupied by the apparatus and to place the articles which are to bestored within the compartment at a convenient height for dispensing. Thecabinet has open- 50 ing 17 in its top'wall forv access to the coolingcompartment, which may be closed by an insulating cover 18.

Referring to Figs. 2 and 3, the cooling compartment includes a metalchamber or container 20 having an opening inits top surrounded by acollar or flange 21, registering with the opening 17. The container isin intimate contact with the evaporator 12 and is enclosed withtheevaporator by insulating side walls 22' and 23, top wall 24, bottomwall 25 and one end wall 26. The top wall has an opening registeringwith the opening 17. The insulating walls are preferably made of slabsof cork or similar material and are permanently secured in place. Theend opposite the wall 26 is left open for a purpose to be described.

The cooling compartment, including the insulating walls, is supportedwithin a cabinet frame having upright frame members 28, preferably ofangle-iron held together by transverse brace plates 29 and 30. The plate29 is preferably of metal and forms a support for the coolingcompartment as well as serving as an impervious facing for the corkwalls. The plate 30 is preferablyof wood and forms the top wall of thecabinet, having the opening 17, previously referred to, and beingcovered with a facing 31 of polished non-corroding metal such as monel.A facing sleeve 32. which may be of insulating material such as fiber.surrounds the opening in the cork top wall 24. This sleeve rests uponthe top of the compartment 20 outside of the collar 21. the facingmember 31 preferably having a flange or collar 33 which fits over theend of the sleeve. -The outer surface of the cabinet is formed byremovable side facing members 35 which extend from top to bottom of thecabinet and also provide themachine compartment walls.

The evaporator which cools the container or compartment 20 is composedof a pair of coils 36 and 37 which are connected in series by aconnection 38. Each coil may be described as generally helical,-that is,it consists of a series of c onvolutions which are not necessarilycircular but which rather conform *to the shape of the compartment to becooled, in this case a rectangle. Each coil is preferably formed bywinding a length of tubing about the container 20 and soldering it tothe container to insure intimate thermal contact. For purposes to bedescribed below the coil 36 starts at a point--between the ends of thecontainer and progresses upwardly to the top of the container, while thecoil '37 begins at the bottom of the container and progresses upwardlyto the point 40 nected by a conduit 44 to the liquid supply end of thecondensing element, and the discharge end of the evaporator; that is theupper end of the lower coil, is connected to the vapor. receiving end ofthe condensing element.

The condensing element may be constructed as described in theapplication of Hull above referred to, and includes generally acompressor driven by a motor 51. for with; drawing gaseous refrigerantfrom the evaporator, a condenser 52 and a fan53 driven by the motor forliquefying the-refrigerant, a receiver 54 for storing the liquidrefrigerant, and a switch contained in the casing-55 operated by athermostat-56 for actuating the motor in response tothe refrigeratingdemand. The thermostat 56 is attached to 'a heat conducting support57which is in intimate thermal contact with the evaporator; The expansionvalve is provided with an air bulb 58 for regulating the amount ofopening of the valve as is more fully disclosed in Hulls applicationreferred to. This bulb is supported by a clip 59 on one of the framemembers 28 as shown in Fig. 2 and in contact'with one of the facingmembers 35 so as to be exposed to the temperature of the atmosphere.

As mentioned above the'cork slab at one end of the'cooling compartmentis omitted, and this provides sufficient space for the thermostat, theexpansion valve, air bulb and the various conduits and connectionsbetween the evaporator and condensing element. After the apparatus hasbeen assembled this space is filled with kapok or other suitablelooseinsulating material.

The motor and compressor of the condensmg unit are supported on afloatingbase 60 which is supported by springs 6L upon a rigid basemember 62 as more fully described in the Hull'application previouslyreferred to. The

rigid base member'62 is rigidly secured to cross braces 63 which extendbetween two of the corner upright members 28. The base thus serves as abrace or stretcher between the the greatest heat leakage into thecabinet oeours and consequently the point at which the reatest amount ofrefrigeration is required is at the top of the cooling compartment wherethe opening 17 is located. For this reason it is proposed to operate theapparatus so that the portion of the evaporator around the top of thecooling compartment is flooded with liquid refrigerant so as to providethe necessary intensity of refrigeration at this point. In order to becertain that the coil is flooded all the way to the top it is necessaryto supply enough refrigerant so that there is a slight overflow ofune-vaporated liquid into the lower coil. Since the lower end of thecompartment requires less refrigeration than the upper end, the smallamount of liquid overflowing into the lower coil will be sufiicient.If'the apparatus were operated at theoretical perfection all of thisliquid would be evaporated in the lower' coil. However, there may be, acertain amount of liquid present in the lower coil of the evaporatorwhen the compressor is stopped by the automatic switch. Since thisoccurs when the evaporator has become very. cold there will be verylittle boiling or evaporation ofthe liquid refrigerant and care must betaken to prevent this-liquid from flowing, by gravity to the compressor.Otherwise evaporation would subsequently occur in the compressor insteadvention as herein disclosed, constitutes a pre- 1 ferred form, it is tobe understood that other pansion type and including a single continuousconduit having an upper section wound about the container from a pointbetween the ends of the container to a point near the top of thecontainer and a lower section wound from a point near the bottom of thecontainer to said point between the ends.

2. Refrigeratin apparatus comprising in combination, a ca inet havingvertical side Walls and a. horizontal top wall enclosing a machinecompartment and a cooling comincluding a pair of tortuous ex ansionchambers connected in series and disposed at different levels, thechambers being so arranged that refrigerant flows upward through thepartrnent above the machine compartment, higher chamber and then upwardthrough the an open-topped container within the cooling compartment, arefrigerating machine in the machine compartment, an evaporatorsurrounding the container and connected to the refrigerating machine forcooling the container, the evaporator being of the dry expansion typeand including a single continuous conduit having an upper section woundabout the container from a point between the ends of the container to apoint near'the top, and a lower section wound from a point near thebottom of the container to said point between the ends, and a regulatingdevice connected to the conduit at the lower end of the upper sectionfor controlling the supply of refrigerant to the conduit.

8. Refrigerating apparatus comprising in combination, a condensingelement and an evaporating element connected in closed circuit relation,the evaporating element being above the level of the condensing elementand including a pair of expansion chambers connected in series anddisposed at different levels, the chambers being so arranged thatrefrigerant flows upward through the higher chamber and then upwardthrough the lower chamber.

4. Refrigerating apparatus comprising in combination, a condensingelement and an evaporating element connected in closed circuit relation,the evaporating element being above the level of the condensing elementand including a pair of generally helical coils disposed in verticalalignment, the lower end of the upper coil being connected to the liquidoutlet of the condensing element, and the upper end of the upper coilbeing connected to the lower end of the lower coil.

5. Refrigerating apparatus comprising in combination, an evaporatorincluding a pair of generally helical coils in vertical align ment, thelower end of the lower coil being connected to the upper end of theupper coil, and means for admitting refrigerant to the lower end of theupper coil.

6. Refrigerating apparatus comprising in combination, a condensingelement and an evaporating element connected in closed circuit relation,the evaporating element being above the level of the condensing elementand including a pair of coils of tubing connected in series and disposedat different levels, the coils being so arranged that refrigerant flowsupward through the higher coil and then upward through the lower coil.

7. Refrigerating apparatus comprising in combination, a condensingelement and an evaporating element connected in closed circuit relation,the evaporating element bein above the level of the condensing elementang lower chamber.

In testimony whereof we hereto aflix our signatures.

HARRY B. HULL. GEORGE F. HOFFERBERTH.

